An existing contact smart card, needing to be inserted into a smart-card terminal unit, must be ensured to be tightly connected with each contact of the interface of the unit; the smart card allows data exchange through contacting of the contact of the smart-card terminal unit with the contact of the smart card and realizes data exchange of the smart card via the standard communication protocol, and thus the contacts must be tightly connected for the contact smart card. As shown in FIG. 1, the drawing on the left shows that the smart card will be inserted into the socket of the unit, and the drawing on the right shows that all the contacts of the smart card have been tightly connected in the unit.
The contact smart card is extensively applied in such fields as telecommunication, finance and medical treatment etc. However, when the contact smart card is used in the corresponding service, it is required that the smart-card terminal unit (the unit that exchanges the data with the smart card according to the application protocol of the specific service) must be connected with the smart card and cannot be separated from it during the service process. Besides, there is a rigid physical mapping between the smart-card terminal unit and the inserted smart card; therefore a given type of smart card can only be used for the specific service.
Most of the existing smart cards with contacts are subjected to a series of international standards. The most basic and important standard is the ISO/IEC 7816 standard. This standard provides not only the physical and electrical characteristics of the smart card but also the transmission protocols to communicate with these smart cards. The standard defines the physical shape and the contacts assignment of such cards and, the electrical circuits of eight contacts (C1 Supply voltage, C2 Reset signal, C3 Clock signal, C4 Reservation, C5 Ground, C6 Variable supply voltage, C7 Data input/output, and C8 reservation). In addition to the ISO/IEC 7816 standard, there are some specific application protocols in the various specific fields where the smart card is probably applied; in China, for example, the SIM and USIM specifications are provided in the communication field, the PBOC specification is provided in the financial field, and all other fields have their own specific specifications. All these application protocols and specifications are established on the underlying protocols of ISO/IEC 7816 standard, and extend the upper-layer protocols of ISO/IEC 7816 standard.
The smart-card terminal unit and the smart card need to achieve the same specific application requirements simultaneously; that is, a specific application protocol is further needed in addition to the basic ISO/IEC 7816 standard for implementing such a service. For example, a mobile equipment can implement the telecommunication service by plugging in a SIM/USIM card, and a prepayment meter can be recharged and show the remaining quantity only after a smart card is inserted into the prepayment meter. The smart card and the smart-card terminal unit using application protocols different from each other are not compatible; sometimes even if in the same field, incompatible application protocols can still prohibit users from using the service; for example, a CDMA mobile equipment can not use a GSM SIM card and vice versa.
At present, both the smart card and the smart-card terminal unit must be connected with conductive contacts and operate in accordance with ISO/IEC 7816 standard, and both the smart-card terminal unit and the smart card have to be bound with the same application protocol, therefore, the specific service under the same application protocol makes it possible to be used only under this combination; for example, a mobile equipment and an SIM/USIM card, an ATM and a ATM card, a prepayment meter and a prepayment card, etc. Such a way is very inflexible, and the user needs to take multiple cards to implement into multiple different devices for different services; even in the same application field, a specified smart-card unit or smart card is also needed for using various services provided by different service providers or the same service provider; for example, in the telecommunication field, for the user who wants to switch between the multiple mobile business plans (these plans can be provided by different operators), if a plan A card provides a low-cost voice plan and a plan B card provides a low-cost data plan, a user who want to enjoy both low cost voice and data plans, will need to either swap the two different SIMs in and out of a single device to use different services, or have to carry two devices in order to use both of these SIM's plans. Such a design and arrangement is cumbersome and not practical in today's fast changing and diverse environment.
Therefore, a new smart card communication system needs to be provided, which can shield the physical mapping requirement between the smart-card terminal unit and the destination smart card, in order to realize flexibility and convenience required in the current fast changing and diverse environment.